Proteoglycans will be isolated from bovine lung and will be subjected to extensive physical and chemical analysis. Size distributions for the proteoglycan subunits will be determined by chromatography and ultracentrifugation. The size and proportion of any proteoglycan aggregate present will also be determined, as will the type and size distribution of the glycosaminoglycans and the amino acid content. Molecular weights of the proteoglycans and glycosaminoglycans, and size parameters such as the hydrodynamic radius will be measured by quasi-elastic light scattering, total intensity light scattering, viscometry and ultracentrifugation. The interactions of lung proteoglycans with tropocollagen and tropoelastin will also be investigated. Circular dichroism spectroscopy will be used to determine the proportion of proteoglycan subunit necessary to give maxium elevation of the denaturation temperature of collagen types I, II and III. Quasi-elastic light scattering will be used to study the size and shape of the aggregates formed in solution-mixtures of tropoelastin and proteoglycans. The morphology of collagen-proteoglycan and elastin-proteoglycan aggregates will be examined in the electron microscope. The interaction results will be correlated with the chemical and physical data for the proteoglycans, to obtain an understanding of the effects of changes in the proteoglycan structure on the macromolecular aggregation.